Dear Dr. Read,
For the first time, Phaser gave the following warning.XXXXXXXWarning:
Input/Default tNCS NMOL (2) does not match suggested NMOL (4): Please check
cell content analysis and tNCS to confirm NMOL
Warning: tNCS is present but correction factors NOT applied
XXXXXXX
Hence, I set NMOL=4 (under other setting using the Phenix GUI of Phaser)
following which, only the second Warning message was displayed. The LLG and
TFZ scores remained the same in both the cases. The warnings remain the same
when I try to place more protomers in the ASU.
XXXXXXX Warning: tNCS is present but correction factors NOT appliedXXXXXXX
However, I found the following message from the log file:XXXXXXXXLarge
non-origin Patterson peaks indicate that multiple tNCS vectors are present
Please analyse peaks for NMOL multiplicity tNCS correction will NOT be
applied To activate tNCS correction, enter tNCS vector manuallyXXXXXXXX
I (think, I have) identified the t-vector (0.500 0.000 0.000) but, don't know
what parameters of Phaser to tweak with. Any suggestions or pointers to
related papers could be very helpful.
I have a similar problem with another dataset of a different protein which is
nearly cylindrical.
Thank,Kaushik
On Saturday, 26 November 2016 11:46 PM, Randy Read <[email protected]> wrote:
Hi,
That message should mean that you didn't ask for a number of molecules
divisible by the order of the tNCS. With that vector you need to search for an
even number of copies.
Let me know if that doesn't explain what you're saying.
Best wishes,Randy Read
----
Randy J. Read
On 25 Nov 2016, at 21:27, KAUSHIK H.S.
<[email protected]> wrote:
Hello,
I have a crystal in C2 spacegroup (94.2073 148.003 72.9967 90 97.6686 90) and
Xtriage predicts 923 residues in ASU. My protein could be anywhere between 95
to 110 residues long (assuming the terminals could be cleaved). Using a
homolog, Phaser gives me a solution with LLG=1072 and TFZ=45. Molrep placed 4
protomers in the ASU however, the crystal packing is poor.
I understand from Phaser that the tNCS is not accounted for (because the
structure is linear?). Is there a way the exact location of the tNCS related
protomers be predicted using information from SfCheck and Xtriage?
Xtriage information:Fraqc. coord. : 0.500 0.000 0.000Distance to origin:
47.104Height relative to origin: 79.688%p_value(height) : 5.283e-07
SFCHECK:
Pseudo-translation is detected: 62.6%Pseudo-translation vector: 0.500 0.000
0.000
Sorry if my question is too naive.
Thanks in advance,Kaushik Hatti,Molecular Biophysics Unit,Indian Institute of
Science,India.
